The semiconductor industry has made significant advancements in its pursuit of higher device density with lower cost. Technological advances in semiconductor device, or integrated circuit (IC), materials and design have produced progressively smaller and more complex circuits. In the course of semiconductor device evolution, functional density (for example, the number of interconnected devices per chip area) has generally increased while geometry sizes have decreased. This scaling down process generally provides benefits by increasing production efficiency and lowering associated costs.
Semiconductor devices may include conductive materials such as copper, nickel, and gold to facilitate conductive interconnections. However, gold may be more reactive and change more readily in composition when exposed to copper, relative to other materials such as nickel. Also, copper may be more reactive and diffuse more readily, relative to other materials such as nickel. Therefore, nickel may be utilized between copper and gold as a buffer to prevent the diffusion of copper into gold.
However, increased functional density has increased the complexity of semiconductor devices, such as by decreasing the distance and amount of different conductive materials on a semiconductor device. This may result in undesirable diffusion and intermixing of different conductive materials, such as between copper and gold, as functional density increases and the distance between conductive materials decreases.
Accordingly, there may be a greater chance of failures per chip area during semiconductor processing. Therefore, conventional semiconductor device fabrication and processing are not entirely satisfactory.